We have established an Environmental Mutagenesis Center within the Biochemistry Department at the University of California, Berkeley. This center unifies the efforts of a number of research groups working on various aspects of mutagenesis. The goal of the program is to understand all aspects of damage to DNA and to evaluate the consequences of this damage. Specific areas of investigation include development of sensitive methods to detect environmental mutagens, detection of these substances in the environment, analysis of their biological transport and metabolic activation. The effects of mutagen action are analyzed by studying chromosome organization, aging, and evolution. The analysis also includes studies of DNA repair and other cellular mechanisms which protect the integrity of DNA.